One of the major problems which is associated with emergency crew operations working at fires is that of visibility. The electrical power is often inoperative, and so there are no light sources in many of the rooms. Even if there were light sources, the smoke and particulate matter is often so thick that they cannot be seen.
Visibility at emergency locations is very important. Rooms must often be traversed to examine other portions of the structure, and those rooms may be filled with obstacles or items which, while innocuous in a normally illuminated scene, become potential traps under the emergency conditions. Firemen and other emergency workers often carry high-intensity halogen flashlights, to aid in seeing. At the emergency location, however, these powerful flashlights often provide little help, because of the blooming or reflection of the light beam from the haze and particulate matter.
Improved light sources are desired for use under conditions of fog, haze and airborne particulate matter.